1. Field of the Invention
The present invention relates to a gas burner for use with an absorption chiller, absorption chiller heater, absorption heat pump, or boiler.
2. Background Art
It has been attempted to reduce a subproduct of nitrogen oxide (referred to as NOx hereinafter) discharged from e.g. a boiler facilitated in an industrial plant or building structure. In particular, the reduction of NOx in a gas burner of the boiler is much concerned.
One of such low NOx gas burners developed by us and submitted previously for patent application is disclosed as shown in FIGS. 1 and 2, which comprises a gas nozzle 31 having a first flame stabilizer 34 mounted to the front end thereof, a second flame stabilizer 33 having e plurality of secondary combustion air passages 30 arranged in the circumferential edge thereof and a primary combustion air passage 36 provided in the center thereof which is defined by the outer surface of the gas nozzle 31, and a burner cone 32 accommodating the second flame stabilizer 33 coupled to the inner wall thereof. In action, radial flows of a fuel gas are blown outward from their respective gas blow apertures 35 so that they come not crossing the secondary combustion air passages 30. Accordingly, the reduction of NOx will be achieved.
When such a conventional gas burner is installed in e.g. a small sized furnace, its fuel gas from the gas blow aperture is dispersed without proper mixture with the secondary combustion air from the secondary air passages. Hence, the resultant combustion flames expand largely up to the inner wall of the furnace thus producing an uncombusted gas, e.g. CO gas.
Further, when it is installed in a large sized furnace having an extensive combustion chamber, its combustion flames become unstable due to combustion pulsation and will produce oscillating combustion.
Furthermore, when it is installed in a recombustion type furnace, its combustion flames hardly reach the innermost of the furnace causing short pass. As the result, the combustion will be declined in efficiency and produce a considerable amount of uncombusted gas, e.g. CO gas.